Description of problem: Setting "ramfb='on'" in the mdev device does not save in the guest xml and only works once Version-Release number of selected component (if applicable): libvirt-6.0.0-24.module+el8.2.1+6997+c666f621.x86_64 qemu-kvm-4.2.0-25.module+el8.2.1+6985+9fd9d514.x86_64 How reproducible: 100% Steps to Reproduce: 1.Edit guest xml to set mdev device with "ramfb='on'": #virsh edit test1 ... <hostdev mode='subsystem' type='mdev' managed='no' model='vfio-pci' display='on' ramfb='on'> <source> <address uuid='03cdd8ec-eacf-4a4a-ae1d-9cacb2bf38d2'/> </source> <alias name='ua-0febf033-9953-40e1-b803-2df42b0bac4e'/> <address type='pci' domain='0x0000' bus='0x07' slot='0x00' function='0x0'/> </hostdev> ... 2.Check the guest xml, no 'ramfb' setting in the mdev device: # virsh dumpxml test1 | grep -A5 mdev <hostdev mode='subsystem' type='mdev' managed='no' model='vfio-pci' display='on'> <source> <address uuid='03cdd8ec-eacf-4a4a-ae1d-9cacb2bf38d2'/> </source> <alias name='ua-0febf033-9953-40e1-b803-2df42b0bac4e'/> <address type='pci' domain='0x0000' bus='0x07' slot='0x00' function='0x0'/> 3.Start the guest again: # virsh start test1 Domain test1 started 4.Check the guest xml, no 'ramfb' setting in the mdev device: # virsh dumpxml test1 | grep -A5 mdev <hostdev mode='subsystem' type='mdev' managed='no' model='vfio-pci' display='on'> <source> <address uuid='03cdd8ec-eacf-4a4a-ae1d-9cacb2bf38d2'/> </source> <alias name='ua-0febf033-9953-40e1-b803-2df42b0bac4e'/> <address type='pci' domain='0x0000' bus='0x07' slot='0x00' function='0x0'/> 5.Check the qemu cmd line, can see the 'ramfb' setting: #ps aux | grep -i ramfb ...-device vfio-pci-nohotplug,id=ua-0febf033-9953-40e1-b803-2df42b0bac4e,sysfsdev=/sys/bus/mdev/devices/03cdd8ec-eacf-4a4a-ae1d-9cacb2bf38d2,display=on,bus=pci.7,addr=0x0,ramfb=on... 6.Destroy the guest: #virsh destroy test1 7.Start the guest: #virsh start test1 8.Check the qemu cmd line: #ps aux | grep -i ramfb no output Actual results: Setting "ramfb='on'" in the mdev device does not save in the guest xml and only works once . Expected results: Should save the 'ramfb' setting in the mdev device. Additional info:
The fix is now upstream: c5815b31976f3982d18c7f6c1367ab6e403eb7eb qemu: format 'ramfb' attribute for mediated devices
Verified with: libvirt-daemon-6.6.0-2.el8.x86_64 qemu-kvm-5.0.0-2.module+el8.3.0+7379+0505d6ca.x86_64 Test steps: 1.Edit guest xml to set mdev device with "ramfb='on'": #virsh edit test1 ... <hostdev mode='subsystem' type='mdev' managed='no' model='vfio-pci' display='on' ramfb='on'> <source> <address uuid='47f3a998-5cbe-4e27-b716-614e6617e916'/> </source> <alias name='ua-0febf033-9953-40e1-b803-2df42b0bac4e'/> <address type='pci' domain='0x0000' bus='0x07' slot='0x00' function='0x0'/> </hostdev> ... 2.Check the guest xml: # virsh dumpxml test1 | grep -A5 mdev <hostdev mode='subsystem' type='mdev' managed='no' model='vfio-pci' display='on'> <source> <address uuid='47f3a998-5cbe-4e27-b716-614e6617e916'/> </source> <alias name='ua-0febf033-9953-40e1-b803-2df42b0bac4e'/> <address type='pci' domain='0x0000' bus='0x07' slot='0x00' function='0x0'/> 3.Start the guest: # virsh start test1 Domain test1 started 4.Check the guest xml: # virsh dumpxml test1 | grep -A5 mdev <hostdev mode='subsystem' type='mdev' managed='no' model='vfio-pci' display='on'> <source> <address uuid='47f3a998-5cbe-4e27-b716-614e6617e916'/> </source> <alias name='ua-0febf033-9953-40e1-b803-2df42b0bac4e'/> <address type='pci' domain='0x0000' bus='0x07' slot='0x00' function='0x0'/> 5.Check the qemu cmd line, can see the 'ramfb' setting: #ps aux | grep -i ramfb ...-device vfio-pci-nohotplug,id=ua-0febf033-9953-40e1-b803-2df42b0bac4e,sysfsdev=/sys/bus/mdev/devices/47f3a998-5cbe-4e27-b716-614e6617e916,display=on,bus=pci.7,addr=0x0,ramfb=on... 6.Destroy guest and start again: #virsh destroy test1 #virsh start test1 7.Check the qemu cmd line, still can see the 'ramfb' setting: #ps aux | grep -i ramfb ...-device vfio-pci-nohotplug,id=ua-0febf033-9953-40e1-b803-2df42b0bac4e,sysfsdev=/sys/bus/mdev/devices/47f3a998-5cbe-4e27-b716-614e6617e916,display=on,bus=pci.7,addr=0x0,ramfb=on...
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (virt:8.3 bug fix and enhancement update), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2020:5137